NVIDIA Tegra30 I2S controller

Required properties:
- compatible : "nvidia,tegra30-i2s"
- reg : Should contain I2S registers location and length
- nvidia,ahub-cif-ids : The list of AHUB CIF IDs for this port, rx (playback)
  first, tx (capture) second. See nvidia,tegra30-ahub.txt for values.

Example:

i2s@70002800 {
	compatible = "nvidia,tegra30-i2s";
	reg = <0x70080300 0x100>;
	nvidia,ahub-cif-ids = <4 4>;
};